整理出15个Android很有用的代码片段

1：查看是否有存储卡插入

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1. String status=Environment.getExternalStorageState();  
2. if(status.equals(Enviroment.MEDIA_MOUNTED))  
3. {  
4.    说明有SD卡插入  
5. }  

2：让某个Activity透明

OnCreate中不设Layout

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1. this.setTheme(R.style.Theme_Transparent);  

以下是Theme_Transparent的定义（注意transparent_bg是一副透明的图片）

3：在屏幕元素中设置句柄
使用Activity.findViewById来取得屏幕上的元素的句柄. 使用该句柄您可以设置或获取任何该对象外露的值.

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1. TextView msgTextView = (TextView)findViewById(R.id.msg);  
2. msgTextView.setText(R.string.push_me);  

4:发送短信

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1. String body=”this is mms demo”;  
2. Intent mmsintent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(”smsto”, number, null));  
3. mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_BODY, body);  
4. mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_COMPOSE_MODE, true);  
5. mmsintent.putExtra(Messaging.KEY_ACTION_SENDTO_EXIT_ON_SENT, true);  
6. startActivity(mmsintent);  

5:发送彩信

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1. StringBuilder sb = new StringBuilder();  
2. sb.append(”file://”);  
3. sb.append(fd.getAbsoluteFile());  
4. Intent intent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(”mmsto”, number, null));  
5. // Below extra datas are all optional.  
6. intent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_SUBJECT, subject);  
7. intent.putExtra(Messaging.KEY_ACTION_SENDTO_MESSAGE_BODY, body);  
8. intent.putExtra(Messaging.KEY_ACTION_SENDTO_CONTENT_URI, sb.toString());  
9. intent.putExtra(Messaging.KEY_ACTION_SENDTO_COMPOSE_MODE, composeMode);  
10. intent.putExtra(Messaging.KEY_ACTION_SENDTO_EXIT_ON_SENT, exitOnSent);  
11. startActivity(intent);  

7：发送Mail

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1. mime = “img/jpg”;  
2. shareIntent.setDataAndType(Uri.fromFile(fd), mime);  
3. shareIntent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(fd));  
4. shareIntent.putExtra(Intent.EXTRA_SUBJECT, subject);  
5. shareIntent.putExtra(Intent.EXTRA_TEXT, body);  

8:注册一个BroadcastReceiver

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1. registerReceiver(mMasterResetReciever, new IntentFilter(”oms.action.MASTERRESET”));  
2. private BroadcastReceiver mMasterResetReciever = new BroadcastReceiver()  
3. {  
4.         public void onReceive(Context context, Intent intent  
5.         {  
6.             String action = intent.getAction();  
7.             if(”oms.action.MASTERRESET”.equals(action))  
8.             {  
9.                 RecoverDefaultConfig();  
10.             }  
11.        }  
12. };  

9:定义ContentObserver，监听某个数据表

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1. private ContentObserver mDownloadsObserver = new DownloadsChangeObserver(Downloads.CONTENT_URI);  
2. private class DownloadsChangeObserver extends ContentObserver  
3. {  
4.         public DownloadsChangeObserver(Uri uri)  
5.         {  
6.             super(new Handler());  
7.         }  
8.         @Override  
9.         public void onChange(boolean selfChange) {}  
10. }  

   

10:获得 手机UA

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1. public String getUserAgent()  
2. {  
3.     String user_agent = ProductProperties.get(ProductProperties.USER_AGENT_KEY, null);  
4.     return user_agent;  
5. }  

11：清空手机上Cookie

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1. CookieSyncManager.createInstance(getApplicationContext());  
2. CookieManager.getInstance().removeAllCookie();  

12：建立GPRS连接

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1. //Dial the GPRS link.  
2. private boolean openDataConnection()  
3. {  
4.     // Set up data connection.  
5.     DataConnection conn = DataConnection.getInstance();      
6.     if (connectMode == 0)  
7.     {  
8.         ret = conn.openConnection(mContext, “cmwap”, “cmwap”, “cmwap”);  
9.     }  
10.     else  
11.     {  
12.         ret = conn.openConnection(mContext, “cmnet”, “”, “”);  
13.     }  
14. }  

13：PreferenceActivity 用法

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1. public class Setting extends PreferenceActivity  
2. {  
3.     public void onCreate(Bundle savedInstanceState)  
4.     {  
5.         super.onCreate(savedInstanceState);  
6.         addPreferencesFromResource(R.xml.settings)；  
7.     }  
8. }  

Setting.xml:

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1. android:key=”seting2″  
2. android:title=”@string/seting2″  
3. android:summary=”@string/seting2″/>  
4. android:key=”seting1″  
5. android:title=”@string/seting1″  
6. android:summaryOff=”@string/seting1summaryOff”  
7. android:summaryOn=”@stringseting1summaryOff”/>  

14:通过HttpClient从指定server获取数据

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1. DefaultHttpClient httpClient = new DefaultHttpClient();  
2. HttpGet method = new HttpGet(“http://www.baidu.com/1.html”);  
3. HttpResponse resp;  
4. Reader reader = null;  
5. try {  
6.     // AllClientPNames.TIMEOUT  
7.     HttpParams params = new BasicHttpParams();  
8.     params.setIntParameter(AllClientPNames.CONNECTION_TIMEOUT, 10000);  
9.     httpClient.setParams(params);  
10.     resp = httpClient.execute(method);  
11.     int status = resp.getStatusLine().getStatusCode();  
12.     if (status != HttpStatus.SC_OK) return false;  
13.     // HttpStatus.SC_OK;  
14.     return true;  
15. } catch (ClientProtocolException e) {  
16.     // TODO Auto-generated catch block  
17.     e.printStackTrace();  
18. } catch (IOException e) {  
19.     // TODO Auto-generated catch block  
20.     e.printStackTrace();  
21. } finally {  
22.     if (reader != null) try {  
23.         reader.close();  
24.     } catch (IOException e) {  
25.         // TODO Auto-generated catch block  
26.         e.printStackTrace();  
27.     }  
28. }  

            
15:显示toast

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1. Toast.makeText(this._getApplicationContext(), R.string._item, Toast.LENGTH_SHORT).show(); 

原文地址：http://blog.csdn.net/keshuiyun/article/details/5968531